Porous carbon materials are extensively used in many modern applications due to their wide availability and excellent physical and chemical properties.1 Some important examples include uses as catalyst supports, adsorbents for separation and gas storage, and in energy storage devices (e.g., batteries). The majority of commercially available porous carbons are microporous (pores<2 nm) and are typically produced by the pyrolysis of organic precursors such as coal, wood, or polymers, followed by a physical or chemical activation step.2 These materials have been used commercially for many years and may be produced in bulk quantities at low cost. Several key drawbacks, however, have been identified for conventional microporous carbons, principally: (i) broad pore-size distributions, (ii) slow mass transport of molecules due to the small pore sizes, (iii) low conductivity due to functionalization incurred during activation, and (iv) collapse of the porous structure during high-temperature treatments.1 Recent development of new nanostructured carbon materials has the potential to address some of these issues and provide new opportunities for applications. In particular the incorporation of larger pores into carbonaceous materials can be advantageous for a range of applications including the adsorption of large molecules, chromatography, electrochemical double-layer capacitors, and lithium ion batteries.3-5 
Template-synthesis of inorganic solids using the self-assembly of lyotropic liquid crystals offers access to materials with well-defined porous structures.7-16 Since it was described in 1992 by Beck et al., liquid crystal templating has become a very important method to developing periodic materials with organization in the 1-100 nm dimension range. Mesoporous solids are typically formed from condensing an inorganic precursor (e.g., tetraethoxysilane) in the presence of a liquid crystalline template followed by the removal of the template. Although ionic surfactants were used in the original invention, diverse molecular (e.g., non-ionic surfactants) and polymeric substances have been used as templates. The materials obtained typically have periodic pores in the mesopore range of 2-50 nm in diameter that may be organized into hexagonal, cubic, or other periodic structures.
In 1999 it was reported that mesoporous silica could act as a hard-template for mesoporous carbon,17 thus providing the first example of a highly ordered mesoporous carbon material. Hard-templating of carbon typically involves the impregnation of a mesoporous “hard-template” with a suitable carbon source and acid catalyst followed by carbonization and selective removal of the template.
FIG. 1 shows a scheme illustrating the way that carbon materials have been previously prepared using hard-templating. In the first step, a surfactant (molecule or polymer) assembles into a liquid crystalline phase (step a), and a silica precursor (and often a catalyst) is added in step b to give a mesostructured silica-surfactant composite, which is isolated. The sacrificial template is then removed by pyrolysis or solvent extraction (step c), to give a mesoporous silica host. Subsequently, the mesoporous silica host is impregnated with a carbon source (e.g., sugar) as shown in step d then pyrolyzed under inert atmosphere as shown in step e to give a mesoporous silica host that is partially loaded with carbon. Besides the high number of steps needed in this route, one of the drawbacks is the difficulty in fully loading the mesoporous host. Consequently, steps d and e are often repeated several times. Once the material is sufficiently loaded (as shown in step f), the silica host is removed with a procedure known to dissolve silica, often using aqueous or alcoholic hydroxide salts (e.g., NaOH, KOH, NH4OH) or hydrogen fluoride (HF) (step g) to give the mesoporous carbon.
In this case the hard-template essentially acts as a mould whose pore structure remains unchanged during the impregnation and carbonization steps. The hard-templates that have been explored are most commonly block-copolymer or surfactant templated periodic mesoporous silicas, such as SBA-15 and MCM-48. Using the approach shown in FIG. 1 and described above, numerous mesoporous carbon materials have been synthesized with various ordered pore structures (e.g., hexagonal and cubic).18-20 Several limitations to this approach exist including (i) the sacrificial use of expensive block-copolymers or surfactants, (ii) the necessity for multiple loading steps, and (iii) the difficulty of synthesizing films and monoliths.1 
Cellulose is the major constituent of wood and plant cell walls and is the most abundant biomaterial on the planet. Cellulose is therefore an extremely important resource for the development of sustainable technologies. The rigid polymeric structure of native cellulose gives rise to excellent mechanical properties but has prevented its use for the hard-templating synthesis of mesoporous carbons as described above. Despite this, the synthesis of mesoporous carbon directly from cellulose could provide a cheap, renewable route to carbon materials. In nature, cellulose exists as the main constituent in the cell wall material of plant and wood fibres which may be regarded as concentric composite tubes whose diameters are on the order of several microns. Stable suspensions of cellulose nanocrystals can be obtained through sulfuric acid hydrolysis of bulk cellulosic material.21 In water, suspensions of nanocrystalline cellulose (NCC) organize into a chiral nematic phase that can be preserved upon air-drying resulting in chiral nematic films.22,23 The high-surface area, unique structural, and self-assembly properties of NCC make it a very interesting potential template for porous materials.
The chiral nematic (or cholesteric) liquid crystalline phase, where mesogens organize into a helical assembly, was first observed for cholesteryl derivatives but is now known to exist for a variety of molecules and polymers. The helical organization of a chiral nematic liquid crystal (LC) results in iridescence when the helical pitch is on the order of the wavelength of visible light due to the angle-dependent selective reflection of circularly polarized light. For this reason, chiral nematic LCs have been extensively studied for their photonic properties and used for applications such as in polarizing mirrors, reflective displays, and lasers.24-26 Incorporation of chiral nematic organization into solid-state structures could provide materials with novel properties. We have recently reported that this may be achieved by using NCC as a lyotropic chiral nematic template.27,28 Various silica precursors may be added to aqueous suspensions of NCC without disrupting the chiral nematic phase and, following slow evaporation, NCC-silica composite films are obtained. We have shown that by removing the NCC, these composite films can be used to produce chiral nematic mesoporous silica that reflects circularly polarized light. Furthermore, the NCC-containing composite films have the potential to be converted to chiral nematic mesoporous carbon by directly using cellulose as the carbon source. This would provide a simple procedure for producing mesoporous carbon from cellulose that could be used for the applications mentioned above. The chirality of these materials could also result in novel properties that have previously not been associated with mesoporous carbon materials.